TWI849121B - Method for manufacturing binaphthylcarboxylic acid - Google Patents

Abstract

An object of the present invention is to provide a new method for manufacturing 2,2’-bis(carboxymethoxy)-1,1’-binaphthyl which is suitable as a resin raw material having excellent optical properties. As a solution, a method for manufacturing 2,2’-bis(carboxymethoxy)-1,1’-binaphthyl is provided, which comprises a step (1) of setting the water content in a solution containing 2,2’-bis(carboxymethoxy)-1,1’-binaphthyl and at least one selected from chain aliphatic ketone having 5 to 8 carbon atoms to be in the range of 2.0% by weight or less and 0.01% by weight or more to perform crystallization.

Description

Method for producing binaphthyl carboxylic acids

The present invention relates to a method for producing binaphthyl carboxylic acids. More specifically, it relates to a method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl using a crystallization solvent composed of a chain aliphatic ketone having 5 to 8 carbon atoms and containing a specific amount of water.

In recent years, polyester resins and polyester carbonate resins using dicarboxylic acid components with a binaphthyl skeleton as polymer components have been highly anticipated as raw materials for optical parts such as optical disks, transparent conductive substrates, and optical filters due to their excellent optical properties such as high refractive index and low birefringence and high heat resistance. Among them, resins produced using 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl (hereinafter also referred to as "Compound A") having the chemical structure shown in the following chemical formula as a polymer component have excellent optical properties and are particularly attracting attention (for example, Patent Documents 1 to 4, etc.).

The method for preparing the compound A represented by the above formula is known to be a method of reacting 1,1'-binaphthyl-2,2'-diol with a halogenated acetate such as ethyl chloroacetate and hydrolyzing the resulting diester as shown in the following reaction formula (for example, Patent Document 5, etc.). However, the compound A obtained by this reaction is often used without being purified, and the crude product is directly converted into an acyl chloride by sulfinyl chloride or oxalyl chloride, etc., and there has been no research or report on a purification method.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 2001-072872

[Patent Document 2] Japanese Patent Publication No. 2018-002893

[Patent Document 3] Japanese Patent Publication No. 2018-002894

[Patent Document 4] Japanese Patent Publication No. 2018-002895

[Patent Document 5] Japanese Patent Publication No. 2008-024650

The present invention is based on the above situation and aims to provide a novel method for producing compound A suitable as a raw material for a resin with excellent optical properties.

The inventors of the present invention have conducted careful research to solve the above problems and found that when using a specific solvent for crystallization, by setting the water content in the crystallization solution to a specific range, the purification yield of high-purity compound A can be improved, thereby completing the present invention.

The present invention is as follows.

1. A method for preparing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl, comprising step (1), wherein the water content in a solution containing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl and one or more chain aliphatic ketones having 5 to 8 carbon atoms is set to a range of 2.0 wt% to 0.01 wt% and crystallization is performed.

2. A method for preparing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl, comprising the following steps (1) and (2),

Step (1): Adjust the water content in the solution containing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl and one or more chain aliphatic ketones selected from 5 to 8 carbon atoms to a range of less than 2.0 wt% and more than 0.01 wt%,

Step (2): Crystallize 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl from the solution of step (1).

3. The method for preparing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl as described in 1. or 2., wherein the 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl in the above step (1) is obtained by reacting 1,1'-binaphthyl-2,2'-diol with halogenated acetic acid or halogenated acetic ester.

According to the present invention, compared with the previous production method, high-purity compound A can be obtained with extremely high yield. In particular, since the purification yield of compound A can be improved, it is an excellent industrial production method.

That is, the provision of the manufacturing method of the present invention is very useful for the industrial use of resin raw materials, etc.

The present invention is described in detail below.

The compound A of the present invention is a compound represented by the following chemical formula.

<About synthesis method>

There is no particular limitation on the synthesis method of compound A of the present invention, but for example, there can be listed: a synthesis method (a) using the well-known 1,1'-binaphthyl-2,2'-diol as a starting material and reacting it with a halogenated acetic acid such as chloroacetic acid; or a synthesis method (b) of reacting it with a halogenated acetic acid ester such as ethyl chloroacetate to obtain an etherification reaction of a diester, followed by hydrolysis of the diester.

In the above synthesis method (a), since the reaction is carried out in the presence of an alkali metal carbonate such as lithium carbonate, sodium carbonate, potassium carbonate or an alkali metal hydroxide such as lithium hydroxide, sodium hydroxide, potassium hydroxide, the target compound A is obtained in the form of an alkali metal salt.

Furthermore, in the above-mentioned synthesis method (b), in order to hydrolyze the diester, an alkali metal hydroxide such as lithium hydroxide, sodium hydroxide, potassium hydroxide, etc. is used in the hydrolysis reaction, so the target compound A is obtained in the form of an alkali metal salt.

That is, in any of the above-mentioned synthesis methods (a) and (b), the obtained alkali metal salt is converted into compound A using an acid, but a water washing treatment is required to remove the inorganic substances generated at this time. The applicants have newly discovered that if the water used in the water washing treatment is carried into the subsequent crystallization step of compound A, the purified yield of compound A obtained by the crystallization step is greatly reduced, and thus the present invention is completed.

<About steps (1) and (2)>

The production method of the present invention is characterized by using one or more crystallization solvents selected from chain aliphatic ketones having 5 to 8 carbon atoms and performing crystallization.

Here, the chain aliphatic ketones with carbon atoms of 5 to 8 that can be used include: diethyl ketone (carbon number 5), methyl isobutyl ketone (carbon number 6), methyl amyl ketone (carbon number 7), methyl hexyl ketone (carbon number 8), etc. Among them, methyl isobutyl ketone, methyl amyl ketone, and methyl hexyl ketone with low water solubility are preferred.

The crystallization solvent in the present invention may also be used in combination with an organic solvent other than a chain aliphatic ketone with 5 to 8 carbon atoms within the scope of not impairing the effect of the present invention, but it is preferably composed only of a chain aliphatic ketone with 5 to 8 carbon atoms.

The compound A used in step (1) of the present invention can be exemplified as: crude crystals obtained by treating a reaction solution containing compound A, crystals obtained by recrystallizing the crude crystals, and residual liquid obtained by diluting the solvent from a solution containing compound A. It can also be amorphous. Compound A itself has two mirror image isomers, but the compound A used in the crystallization step of the present invention is preferably a racemate, and the obtained crystals are also preferably a racemate.

In step (1) of the manufacturing method of the present invention, it is important to set the water content in the solution to be crystallized to a range of 2.0 wt% or less and 0.01 wt% or more. The upper limit is preferably 1.7 wt% or less, and more preferably 1.0 wt% or less. Furthermore, the lower limit is preferably 0.03 wt% or more, and more preferably 0.05 wt% or more.

In addition, the moisture content in the present invention refers to the moisture content measured by the Karl Fischer method.

Relative to 100 parts by weight of compound A, the amount of the chain aliphatic ketone having 5 to 8 carbon atoms used in step (1) is preferably 250 to 1000 parts by weight, more preferably 300 to 800 parts by weight, and even more preferably 400 to 600 parts by weight. When the temperature is raised to dissolve all the crystals, it can be done under normal pressure or under pressure. When the temperature is below 450 parts by weight, it is preferably under pressure.

It is sufficient to adjust the water content in the solution obtained by dissolving compound A in a chain aliphatic ketone having 5 to 8 carbon atoms to a range of 2.0 wt% or less and 0.01 wt% or more, and then cool it to crystallize. For example, while distilling the chain aliphatic ketone from the solution, adjusting the water content in the residual solution to a range of 2.0 wt% or less and 0.01 wt% or more, and then cooling it to crystallize is a simple method.

In step (2) of the present invention, the temperature for crystallization is preferably 90 to 120°C, more preferably 95 to 105°C. The time taken for solvent distillation is preferably 2 to 15 hours, more preferably 4 to 10 hours, and even more preferably 6 to 8 hours.

The cooling rate during crystallization and after crystallization is preferably 5 to 15°C per hour, more preferably 7 to 12°C. Furthermore, when crystallizing, seed crystals may not be used, but it is preferred to use seed crystals, and crystals obtained by a known manufacturing method or crystals obtained by precipitation without seed crystals can be used as seed crystals. The final cooling temperature is preferably 20 to 60°C, more preferably 25 to 35°C. After cooling to the above temperature, the precipitated crystals are separated by filtering.

<About drying steps>

The crystals obtained by crystallization are dried to remove the solvent used in the crystallization. The crystals obtained by crystallization can be dried under normal pressure or under reduced pressure. However, when it is implemented in industry, it is more efficient to implement it under reduced pressure, and it is also better in terms of removing the solvent used in the crystallization. It is preferably implemented at 60 to 120°C under reduced pressure, and more preferably at 70 to 110°C under reduced pressure.

[Implementation example]

The present invention is described in more detail below through examples, but the present invention is not limited to these examples.

1. Analysis method of moisture content

Measuring machine: Karl Fischer MKS-520 (manufactured by Kyoto Electronics Co., Ltd.)

AQUAMICRON Titrant SS 3mg was used as the titrant for titration, and the water content was determined by volumetric titration.

2. About the purity analysis method

Measuring device: High performance liquid chromatography analyzer (manufactured by Shimadzu Corporation)

Pump: LC-20AD

Column oven: CTO-20A

Detector: SPD-20A

Column: HALO-C18

Oven temperature: 50℃

Flow rate: 0.7ml/min

Mobile phase: (A) acetonitrile, (B) 0.1 vol% phosphoric acid water

Gradient conditions: (A) Volume % (time from start of analysis)

30%(0min)→100%(12min)→100%(15min)

Detection wavelength: 280nm

After determination under the above conditions, the purity (%) of the target compound obtained in the following examples and comparative examples is calculated using the liquid chromatography calibration curve of the target compound.

<Synthesis Example 1>

Synthesis of 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl potassium salt

1,1'-binaphthyl-2,2'-diol 1213g, acetonitrile 3638g, potassium carbonate 1346g, potassium iodide 121g were added to a four-necked flask, the temperature was raised to 70°C, and stirred at the same temperature for 1 hour. After preparing a mixed solution of ethyl chloroacetate 1460g and N-methylpyrrolidone 13g, the mixed solution was dripped while the temperature of the reaction solution was maintained at 70 to 80°C. After stirring for 6 hours, 3032g of water was added and the temperature was raised to 70°C, and the water layer was removed. Then, 3392g of 35% potassium hydroxide aqueous solution was dripped while the temperature of the reaction solution was maintained at 70 to 80°C. After 2 hours, the reaction solution was slowly cooled and filtered at 25°C to obtain 2180 g of crystals of 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl potassium salt.

<Implementation Example 1>

50.0 g of crystals obtained by drying the potassium salt obtained in Synthesis Example 1, 100 g of water, and 265 g of methyl isobutyl ketone were added to a four-necked flask and heated to 80°C to dissolve. 30.0 g of concentrated hydrochloric acid was dripped while maintaining the temperature at 80 to 85°C, and stirred at the same temperature for 30 minutes. After standing, the water layer was drawn out, and water was added to the obtained oil layer, stirred, and the water layer was separated and removed for multiple times until the pH of the water layer reached 4. Then, water and 147 g of methyl isobutyl ketone were distilled out from the obtained oil layer under normal pressure. During distillation at 95°C, seed crystals obtained by a previously known manufacturing method were added and the precipitation of crystals was confirmed. The water content in the residual solution after distillation was 0.1%. The residual solution was cooled to 30°C at a cooling rate of 10°C per hour, filtered, and then dried to obtain 38.3g of crystals of compound A. The yield was 91.0% and the purity was 99.9%.

<Implementation Example 2>

50.0 g of crystals obtained by drying the potassium salt obtained in Synthesis Example 1, 100 g of water, and 265 g of methyl isobutyl ketone were added to a four-necked flask and heated to 80°C to dissolve. 30.0 g of concentrated hydrochloric acid was dripped while maintaining the temperature at 80 to 85°C, and stirred at the same temperature for 30 minutes. After standing, the water layer was drawn out, and water was added to the obtained oil layer, stirred, and the water layer was separated and removed for multiple times until the pH of the water layer reached 4. Then, water and 147 g of methyl isobutyl ketone were distilled out from the obtained oil layer under normal pressure. During distillation, at 95°C, seed crystals obtained by a previously known manufacturing method were added and the precipitation of crystals was confirmed. After that, water was added so that the water content in the residual solution became 0.4%, and the residual solution was cooled to 30°C at a cooling rate of 10°C per hour, filtered, and then dried to obtain 38.2g of crystals of compound A. The yield was 90.9% and the purity was 99.9%

<Implementation Example 3>

In the above Example 2, the same operation was performed except that the water content in the residual solution after distilling off water and methyl isobutyl ketone was adjusted to 0.7%, and 38.2 g of crystals of compound A were obtained. The yield was 90.9% and the purity was 99.9%.

<Implementation Example 4>

In the above Example 2, the same operation was performed except that the water content in the residual solution after distilling off water and methyl isobutyl ketone was adjusted to 1.0%, and 37.8g of crystals of compound A were obtained. The yield was 90.1% and the purity was 99.9%.

<Implementation Example 5>

In the above Example 2, the same operation was performed except that the water content in the residual solution after distilling off water and methyl isobutyl ketone was adjusted to 1.3%, and 36.8g of crystals of compound A were obtained. The yield was 87.7% and the purity was 99.9%.

<Implementation Example 6>

In the above Example 2, the same operation was performed except that the water content in the residual solution after distilling off water and methyl isobutyl ketone was adjusted to 1.7%, and 36.4 g of crystals of compound A were obtained. The yield was 86.6% and the purity was 99.9%.

<Comparison Example 1>

In the above Example 2, the same operation was performed except that the water content in the residual solution after distilling off water and methyl isobutyl ketone was adjusted to 2.1%, and 33.4 g of crystals of compound A were obtained. The yield was 79.5% and the purity was 99.9%.

<Comparison Example 2>

The same operation was performed except that the methyl isobutyl ketone used in the above Example 1 was replaced with methyl ethyl ketone, and the water content in the solution was set to 0.1%, and 33.9g of crystals of compound A were obtained. The yield was 80.7% and the purity was 99.9%.

<Comparison Example 3>

In the above-mentioned comparative example 2, the same operation was performed except that the amount of water and methyl ethyl ketone distilled out was set to 210g and the water content in the solution was changed to 3.2%, and 21.7g of crystals of compound A were obtained. The yield was 51.7% and the purity was 99.9%.

<Comparison Example 4>

The same operation was performed except that the methyl isobutyl ketone used in the above Example 1 was replaced with cyclohexanone. The water content in the solution was set to 0.1%, and 32.2 g of crystals of compound A were obtained. The yield was 76.7% and the purity was 99.9%.

<Comparison Example 5>

In the above-mentioned comparative example 4, the same operation was performed except that the water content in the solution was changed to 1.5%, and 20.5 g of crystals of compound A were obtained. The yield was 48.8% and the purity was 99.9%.

<Comparison Example 6>

50.0 g of the crystals obtained by drying the potassium salt obtained in the above-mentioned Synthesis Example 1, 100 g of water, and 265 g of MIBK were added to a four-necked flask and heated to 80°C to dissolve. 30.0 g of concentrated hydrochloric acid was dripped while maintaining the temperature at 80 to 85°C, and stirred at the same temperature for 30 minutes. After standing, the water layer was drawn out, and the water layer was washed with water by adding water to the obtained oil layer, stirring, and separating and removing the water layer several times until the pH of the water layer reached 4. Without adjusting the water content in the oil layer, the oil layer was cooled to 30°C at a cooling rate of 10°C per hour and filtered, and then dried to obtain 24.9g of 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl crystals. The yield was 59.2% and the purity was 99.9%. In addition, the water content in the above oil layer was 5.2%.

The test results of the above-mentioned Examples 1 to 6 and Comparative Examples 1 to 6 are summarized and shown in the following Table 1.

As shown in Table 1, it can be seen that by using methyl isobutyl ketone and setting the water content in the solution to a range of less than 2.0 wt% and more than 0.01 wt% (Examples 1 to 6), the purification yield of compound A with a purity of 99.9% is more than 85%. In addition, it can be confirmed that the efficiency of obtaining high-purity compound A is fully improved compared to the production method without adjusting the water content (Comparative Example 6).

Furthermore, from the results of Comparative Example 1, it can be seen that when the water content in the solution is set to the range of 2.0 wt% or less and 0.01 wt% or more, it has a critical significance.

Furthermore, from the results of Comparative Examples 2 to 5, it can be confirmed that the excellent improvement effect of the purification yield of high-purity compound A is achieved by using a specific solvent.

From the above results, it can be seen that the effect obtained by the production method of the present invention is a particularly significant effect with critical significance, wherein the production method of the present invention uses a chain aliphatic ketone with 5 to 8 carbon atoms and sets the water content in the solution to a range of less than 2.0 weight % and more than 0.01 weight %.

Claims (3)

A method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl comprises step (1), wherein the water content in a solution containing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl and one or more selected from methyl isobutyl ketone, methyl amyl ketone and methyl hexyl ketone is set to a range of 1.7 wt% to 0.01 wt% and crystallizes. A method for preparing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl comprises the following steps (1) and (2): Step (1): adjusting the water content in a solution containing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl and one or more selected from methyl isobutyl ketone, methyl amyl ketone and methyl hexyl ketone to a range of less than 1.7 wt% and more than 0.01 wt%. Step (2): crystallizing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl from the solution of step (1). The method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl as described in claim 1 or 2, wherein the 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl in step (1) is obtained by reacting 1,1'-binaphthyl-2,2'-diol with halogenated acetic acid or halogenated acetic ester.